1. Field of the Invention
The invention relates to a device for retracting tissue at a surgical wound. The retraction device of the invention is particularly useful during back surgery in conjunction with a kneeling attachment including a platform on which a patient kneels with the torso positioned over one end of an operating table while the buttocks rest against a buttocks support. The novel retraction device can also be used during back surgery on a prone, face-down patient.
2. Description of Related Art
U.S. Pat. No. 4,254,763 (McCready et al.) reports that in "surgical operations on the chest or abdomen, it is customary to employ a retraction apparatus. Most, if not all, versions of the retraction apparatus are attached directly to the operating room table by means of affixation to a rail which is provided along each side of the table. Whether by connection to one or both rails, the retraction apparatus generally provides a framework extending over the region of the patient in which the operation is to be performed. One or more retractor blades are attached to the framework, and these blades are positioned in the incision and serve to hold back tissue, organs, and the like so that the surgeon may operate on the intended area" (col. 1, lines 11-27). While the McCready framework includes a ring-like frame from which retractors are suspended, a number of patents show rectangular frames. See, for example, U.S. Pat. No. 3,522,799 (Gauthier), No. 3,221,743 (Thompson et al.). No. 3,572,326 (Jensen), and No. 4,355,631 (LeVahn). Other U.S. patents showing ring-like frames include No. 2,586,488 (Smith), 2,594,086 (Smith), and 3,040,739 (Grieshaber). A frame of different shape is shown in U.S. Pat. No. 4,617,916 (LeVahn et al.). The framework of each of these patents is supported by siderails of the operating table, except that we fail to find in Gauthier any mention of support for his framework.
Apparatus like that shown in the LeVahn et al. patent is sold for use in abdominal surgery as the Omni-Tract 3005 Upper Abdominal/Bariatric Retractor System by Minnesota Scientific, Inc., Minneapolis, MN. The Omni-Tract framework includes a "crossbar" that is clamped by one or two posts to one or both rails of an operating table. Universal joints at the top of each of the posts permit the crossbar to be adjusted to the desired height and lateral distance from the surgical wound. Retractors can be mounted on the crossbar using universal clamps which can be swiveled to provide the desired lateral retraction from positions that do not obstruct access to the wound. Such universal clamps involve elaborate sequences to be connected, readjusted or disconnected and thus do not permit quick response to urgent situations.
Because of the far greater force needed to retract the powerful muscles of the back, certain abdominal muscles, and the thoracic cage, the above-discussed frameworks are not said to be useful for such purposes. Furthermore, it is believed that no framework is available that would be suitable for supporting retractors above a surgical wound in the back. Instead of using such a framework, it is quite common in back surgery for a surgical assistant to hold a Hibbs-type retractor in place manually, sometimes for several hours. Not only does this fully occupy the assistant, but there is a danger that the assistant could move the retractor in a hazardous manner, and the danger could be amplified due both to fatigue and to boredom.
When it is desired to attach accessories to an operating table, the most common attachment devices are Clark sockets such as No. 5393 of Orthopedic Systems, Inc., Hayward, CA. The Clark sockets are designed to be clamped to a side rail of the operating table and are so made that all degrees of freedom are loosened at once. Thus, in order to move the patient's buttocks away from or closer to the head of the operating table, a Clark socket is unclamped, also releasing its hold on the accessory. The head-to-foot adjustability of a Clark socket is limited to rather large angular steps. Other sockets and clamps are currently available, but it is believed that they have the same limitations as do Clark sockets.